CN111826708A

CN111826708A - Upper lifting vacuum furnace

Info

Publication number: CN111826708A
Application number: CN202010830826.6A
Authority: CN
Inventors: 王宇; 官伟明; 梁振兴
Original assignee: Meishan Boya New Materials Co ltd
Current assignee: Meishan Boya New Materials Co ltd
Priority date: 2019-08-21
Filing date: 2020-08-18
Publication date: 2020-10-27
Also published as: CN110344108A

Abstract

The application discloses a top-pulling vacuum furnace. Comprises a hearth, a lifting rod, a movement device and a control system; a temperature field and a heat source are arranged in the hearth; at least one part of the lifting rod is positioned in the hearth, and the moving device is in transmission connection with the lifting rod so as to drive the lifting rod to move up and down and/or rotate; the control system is used for controlling the movement direction and/or the movement speed of the movement device. The lifting vacuum furnace can realize automatic control of the crystal growth process, the prepared single crystal material has good structural consistency, the welding process is improved, and the sealing property and the corrosion resistance of a hearth are improved.

Description

Upper lifting vacuum furnace

PRIORITY INFORMATION

This application claims priority to chinese application No. 201910772691.X filed on 21/08/2019, the entire contents of which are incorporated herein by reference.

Technical Field

The application relates to the field of crystal materials, in particular to a crystal growth device.

Background

The single crystal furnace is used for preparing silicon, germanium, gallium arsenide, yttrium aluminium garnet (Y)₃Al₅O₁₂YAG for short), lutetium silicate (Lu)₂SiO₅LSO) and the like, which is a comprehensive system integrating the disciplines of machinery, electricity, computers, aerodynamics, hydrodynamics, thermodynamics and the like. At present, the operation and control system of the domestic pull-up high-temperature crystal growth vacuum induction furnace is basically semi-automatic, the crystal growth process (such as the technical processes of seeding, necking, shouldering, constant diameter, ending, cooling and the like) can not be fully automatically controlled, the dependence degree of the crystal growth process on operators is high, and the consistency of the crystal growth can not be ensured. The fully automatic single crystal growth induction furnace imported from abroad is expensive and difficult to maintain, and is not suitable for mass purchase. In addition, the inner wall of the hearth wall of the double-layer stainless steel water-cooling structure is generally welded on two sides, the outer wall of the hearth wall is welded on one side, gaps may exist in the inner wall welded on two sides, and therefore air remains, and in the process of expansion with heat and contraction with cold, the gaps of the air remains may crack to cause the problem that the vacuum environment is affected or cooling media leaks.

Disclosure of Invention

Based on this, the present application provides a crystal growth apparatus for preparing a single crystal material.

One embodiment of the present application provides a crystal growth apparatus. The device comprises a hearth, a lifting rod, a moving device and a control system; a temperature field and a heat source are arranged in the hearth; at least one part of the lifting rod is positioned in the hearth, and the moving device is in transmission connection with the lifting rod so as to drive the lifting rod to move up and down and/or rotate; the control system is used for controlling the movement direction and/or the movement speed of the movement device.

In some embodiments, a first cooling structure is disposed on at least a portion of the furnace wall.

In some embodiments, at least a portion of the furnace wall comprises an inner wall and an outer wall, the inner wall and the outer wall enclosing a closed space for filling with a cooling medium; and the outer wall is provided with a cooling medium inlet and a cooling medium outlet.

In some embodiments, the furnace further comprises a furnace door having a second cooling structure disposed thereon.

In some embodiments, the furnace door comprises an inner door wall and an outer door wall, the inner door wall and the outer door wall enclose a closed space, and the closed space is filled with a cooling medium; and a cooling medium inlet and a cooling medium outlet are formed in the outer wall of the door.

In some embodiments, at least a portion of the furnace door is transparent.

In some embodiments, the motion device comprises: a lifting component and a rotating component; the lifting assembly is used for controlling the lifting rod to move up and down; the lifting assembly comprises: the device comprises a stand column, a slide block, a screw rod and a first driving unit; the first driving unit is arranged at the top of the upright post; the upright post is provided with a slide rail; the screw rod is arranged in parallel with the slide rail, and one end of the screw rod is connected with the first driving unit; the sliding block is sleeved on the screw rod and is in threaded fit with the screw rod; at least one part of the sliding block is positioned in the sliding rail, and the sliding block can be driven to move up and down along the sliding rail by the rotation of the screw rod; the rotating assembly is used for controlling the rotation of the lifting rod; the rotating assembly is arranged on the sliding block.

In some embodiments, the apparatus further comprises a weighing device for detecting the weight of the crystal on the lifting rod, the weighing device being disposed on the slider.

In some embodiments, the control system has a signal connection with the weighing device for receiving an output signal of the weighing device.

In some embodiments, the rotating assembly comprises a second drive unit and a transmission assembly; the second driving unit can drive the weighing device to rotate through the transmission assembly.

In some embodiments, the drive assembly includes a pulley and a belt; the output rotating shaft of the second driving unit is connected with the rotating shaft of the belt pulley; at least one belt is sleeved on the belt pulley and the weighing device.

In some embodiments, the weighing apparatus comprises a weighing chamber and a load cell; the weighing sensor is arranged inside the weighing chamber; one end of the weighing sensor is fixedly connected with the lifting rod; the other end of the weighing sensor is fixedly connected with the weighing chamber.

In some embodiments, the lifting rod comprises at least a middle rod and a seed rod; one end of the middle rod is fixedly connected with the weighing chamber; the middle rod penetrates through a through hole formed in the sliding block; the middle rod has a hollow structure; the seed rod penetrates through the middle rod; one end of the seed rod is connected with the weighing sensor; the other end of the seed rod is used for connecting a seed crystal.

In some embodiments, the device further comprises a sealing sleeve: one end of the sealing sleeve is hermetically connected with the top of the hearth, and the lifting rod is positioned in the sealing sleeve; the part of the top of the hearth, which is connected with the sealing sleeve in a sealing way, is provided with a through hole so that the lifting rod can pass through the through hole; the other end of the sealing sleeve is connected with the lower end face of the sliding block in a sealing mode.

In some embodiments, the device further comprises a vacuum device; the vacuum device is used for providing a vacuum environment or an air pressure environment lower than the standard atmospheric pressure for the interior of the hearth.

Drawings

The present application will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a schematic view of a crystal growing apparatus according to some embodiments of the present application;

FIG. 2A is a longitudinal cross-sectional view of a furnace according to some embodiments of the present application;

FIG. 2B is a horizontal cross-sectional view of a furnace according to some embodiments of the present application;

FIG. 3 is a schematic structural view of a pulling assembly according to some embodiments of the present application;

FIG. 4 is a schematic structural view of a rotating assembly according to some embodiments of the present application;

FIG. 5 is a schematic diagram of a weighing apparatus according to some embodiments of the present application; and

FIG. 6 is a schematic diagram of a crystal growth apparatus according to some embodiments of the present application.

In the figure, 100 is a crystal growing device, 110 is a hearth, 120 is a lifting rod, 130 is a moving device, 131 is a lifting component, 132 is a rotating component, 133 is a weighing device, 111 is a temperature field, 111-1 is a crucible, 111-2 is an alumina tube, 112 is a heat source, 113 is a hearth wall, 113-1 is an inner wall, 113-2 is an outer wall, 113-3 is an inner wall and an outer wall form a closed space, 114 is a hearth door, 114-1 is an inner door wall, 114-2 is an outer door wall, 114-3 is an inner door wall and an outer door wall form a closed space, 115 is a furnace frame, 1311 is a vertical column, 1312 is a sliding block, 1313 is a lead screw, 1314 is a first driving unit, 1314-1 is a lifting motor, 1314-2 is a lifting driver, 1314-3 is a speed reducer, 1314-4 is a shaft connector, 1314-5 is a mounting seat, 1321 is a second driving unit, 1321-1 is a rotating motor, 1321-2 is a rotary driver, 1321-3 is a mounting seat, 1322 is a transmission component, 1322-1 is a belt pulley, 1322-2 is a belt, 1331 is a weighing chamber, 1332 is a weighing sensor, 121 is a middle rod, 122 is a seed rod, and 140 is a sealing sleeve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

On the contrary, this application is intended to cover any alternatives, modifications, equivalents, and alternatives that may be included within the spirit and scope of the application as defined by the appended claims. Furthermore, in the following detailed description of the present application, certain specific details are set forth in order to provide a better understanding of the present application. It will be apparent to one skilled in the art that the present application may be practiced without these specific details.

The embodiment of the application relates to a crystal growth device, which can be used for preparing single crystal materials such as scintillation crystals and laser crystals, and the single crystal materials can be applied to the fields of medical instrument imaging, safety inspection, industrial nondestructive inspection, lasers and the like.

FIG. 1 is a schematic view of a crystal growth apparatus 100 according to some embodiments of the present application; FIG. 2A is a longitudinal cross-sectional view of a furnace 110 according to some embodiments of the present application; FIG. 2B is a horizontal cross-sectional view of furnace 110 according to some embodiments of the present application. The crystal growth apparatus 100 and the furnace 110 according to the embodiment of the present application will be described in detail below with reference to fig. 1 and 2A to 2B. It should be noted that the following examples are only for explaining the present application and do not constitute a limitation to the present application.

In an embodiment of the present application, as shown in FIG. 1, the crystal growing apparatus 100 may include a furnace 110, a lifting rod 120, a movement device 130, and a control system (not shown).

In the embodiment of the present application, as shown in fig. 2A-2B, a temperature field 111 and a heat source 112 may be disposed in the furnace 110 for providing a desired field and temperature for crystal growth. For example, the temperature may be 2200 ℃. In some embodiments, the furnace 110 may be a cylinder, cube, or cuboid for providing a site for crystal growth. For example, the hearth 110 may have a cylindrical structure with a diameter of 400-900 mm and a height of 500-1200 mm. In some embodiments, the thermal field 111 is used to provide a temperature environment for crystal growth, and the thermal field 111 may include a crucible 111-1 (e.g., an iridium crucible) and an alumina tube 111-2, and the alumina tube 111-2 and the crucible 111-1 may be arranged vertically and concentrically and outside the crucible 111-1 to maintain a stable temperature around the crucible 111-1 and to uniformly heat the material in the crucible 111-1. In some alternative embodiments, the alumina tube 111-2 may be replaced with a zirconia tube. In some alternative embodiments, the zirconia tube may be sleeved outside the alumina tube, or the alumina tube may be sleeved outside the zirconia tube, and the alumina tube and the zirconia tube are concentrically arranged and located outside the crucible 111-1. In some alternative embodiments, the zirconia tubes may also be replaced with hollow cylinders of zirconia bricks. In some embodiments, the heat source 112 may be a heating coil for providing the heat required for crystal growth. In some embodiments, the heating coil may have an inner diameter (250 to 330mm) x a height (155 to 270mm) x (7 to 9 turns). In some embodiments, the heat source 112 can be vertically disposed concentrically with the crucible 111-1 and the alumina tube 111-2, and outside the alumina tube 111-2. In some embodiments, the crucible 111-1 may be located at the center of the hearth 110 and coincide with the central axis of the lifting rod 120 for containing the raw material for crystal growth.

In an embodiment of the present disclosure, as shown in fig. 1, at least a portion of the lifting rod 120 may be located in the firebox 110, and the moving device 130 and the lifting rod 120 may have a transmission connection (e.g., a bolt connection, a welding connection, a hinge connection, a snap connection, etc.) to drive the lifting rod 120 to move up and down and/or rotate. In some embodiments, the bottom of the lifter 120 may be attached to a seed crystal to seed crystal growth. In some embodiments, the movement device 130 can include a lifting assembly 131, a rotating assembly 132, and a weighing device 133, and is located at the top of the firebox 110. In some embodiments, a control system may be used to control the direction and/or speed of movement of the motion device 130. Specifically, the control system can control the movement direction and/or the movement speed of the movement device 130, the movement device 130 is in transmission connection with the lifting rod 120, the bottom of the lifting rod 120 can be connected with the seed crystal and is located in the hearth, and the lifting rod 120 and the seed crystal can be driven to move up and down and/or rotate through the movement of the movement device 130 to control the crystal growth.

In an embodiment of the present application, as shown in FIGS. 2A-2B, at least a portion of the furnace wall 113 may be provided with a first cooling structure for controlling the temperature of the furnace wall to protect operator safety. In some embodiments, at least a portion of the furnace wall 113 may include an inner wall 113-1 and an outer wall 113-2, the inner and outer walls enclosing a closed space 113-3 for filling with a cooling medium; the outer wall may be provided with a cooling medium inlet and a cooling medium outlet. In some embodiments, the inner wall may be made of 5-10 mm thick austenitic stainless steel (316L), and the outer wall may be made of 4-8 mm thick austenitic stainless steel (304L). In some embodiments, the distance between the inner wall and the outer wall can be set to be 5-10 mm. In some embodiments, the inner wall and the outer wall may be welded by a welding method such as metal-inert-gas (MIG) welding or tungsten-inert-gas (TIG) welding. In some embodiments, the cooling medium may be water, ethanol, ethylene glycol, isopropanol, n-hexane, or the like, or any combination thereof, e.g., may be a 50:50 mixture of water and ethanol. In some embodiments, the first cooling structure may include a plate-type cooling structure or a tube-type cooling structure, or may be other reasonable structures known to those skilled in the art, which is not limited by the present application. In some embodiments, the first cooling structure may be connected to a driving device (e.g., a cooling water pump) for a cooling medium through a pipe to cool the furnace wall by circulation of the cooling medium.

In an embodiment of the present application, as shown in FIG. 2B, the furnace 110 may further include furnace doors 114 having a second cooling structure disposed thereon for controlling the temperature of the furnace wall to protect operator safety. In some embodiments, the furnace doors may include an inner door wall 114-1 and an outer door wall 114-2 that enclose a closed space 114-3 for filling with a cooling medium; the outer wall of the door can be provided with a cooling medium inlet and a cooling medium outlet. In some embodiments, the inner door wall may be formed of 5-10 mm thick austenitic stainless steel (316L) and the outer door wall may be formed of 4-8 mm thick austenitic stainless steel (304L). In some embodiments, the distance between the inner wall of the door and the outer wall of the door can be set to be 5-10 mm. In some embodiments, the inner wall and the outer wall of the door can be welded by using a welding method such as metal-inert-gas (MIG) welding or tungsten-inert-gas (TIG) welding. In some embodiments, the cooling medium may be water, ethanol, ethylene glycol, isopropanol, n-hexane, or the like, or any combination thereof, e.g., may be a 50:50 mixture of water and ethanol. In some embodiments, the first cooling structure and the second cooling structure may be the same or different cooling media. In some embodiments, the second cooling structure may include a plate-type cooling structure or a tube-type cooling structure, or may be other reasonable structures known to those skilled in the art, which is not limited by the present application. In some embodiments, the first cooling structure and the second cooling structure may be the same or different cooling structures. In some embodiments, the second cooling structure can be connected with a driving device (such as a cooling water pump) of a cooling medium through a pipeline, and the furnace door is cooled through circulation of the cooling medium.

In some embodiments, at least a portion of the furnace door can be a transparent material. In some embodiments, the transparent material may be disposed on the inner wall and the outer wall of the door at the same time, and the inner wall and the other parts of the outer wall of the door together form a closed space for filling a cooling medium to cool. In some embodiments, the transparent material may be a high temperature resistant glass or polymer composite material, or other reasonable materials known to those skilled in the art, which is not limited in this application. Through the transparent material on this furnace door, operating personnel can observe the growth condition of the inside crystal of furnace in real time.

In some embodiments, the firebox 110 may further include a frame 115 and be fixedly coupled (e.g., bolted, welded, hinged) to the frame 115, the frame 115 being used to mount the firebox 110 such that the firebox 110 is horizontal. For example, the levelness is 0.05/1000. In some embodiments, the stove rack 115 may be a cubic or cylindrical steel frame structure. For example, the furnace frame 115 is made of a rectangular tube having a length (800 to 1600mm), a width (800 to 1600mm), and a height (300 to 600mm) of (80 to 150mm) × (80 to 150 mm). In some embodiments, the legs of the hob 115 may be round or square steel tubes. In alternative embodiments, the stove rack 115 may be other reasonable structures known to those skilled in the art, and the present application is not limited thereto.

FIG. 3 is a schematic diagram of the construction of a pull assembly 131 according to some embodiments of the present application; FIG. 4 is a schematic diagram of a structure of a rotation assembly 132 according to some embodiments of the present application; FIG. 5 is a schematic diagram of a weighing apparatus 133 according to some embodiments of the present application. The exercise device 130 according to the embodiment of the present application will be described in detail with reference to fig. 3 to 5. It should be noted that the following examples are only for explaining the present application and do not constitute a limitation to the present application.

In some embodiments, the movement device 130 can include a lifting assembly 131, a rotating assembly 132, and a weighing device 133, and is located at the top of the firebox 110.

In an embodiment of the present application, as shown in fig. 3, the lifting assembly 131 may include a column 1311, a slider 1312, a lead screw 1313, and a first driving unit 1314 for controlling the up-and-down movement of the lifting rod 120. In some embodiments, the first driving unit 1314 may include a pull-up motor 1314-1, a pull-up driver 1314-2, a speed reducer 1314-3, and a mounting seat 1314-5, and the pull-up motor 1314-1, the pull-up driver 1314-2, and the speed reducer 1314-3 may be fixedly disposed on the top of the upright 1311 via the mounting seat 1314-5. In some embodiments, the fixed arrangement may be bolted, welded, or hinged. In some embodiments, the columns 1311 may be provided with sliding rails, and the lower ends of the columns 1311 may be fixedly connected (e.g., bolted, welded, hinged, clamped, etc.) to the furnace frame 115. In some embodiments, the lead screw 1313 can be disposed parallel to the slide rail, and one end of the lead screw 1313 can be fixedly connected (e.g., bolted, welded, hinged, clamped, etc.) to the speed reducer 1314-3 via the coupling 1314-4. The rotational direction and rotational speed of the lead screw 1313 can be controlled by controlling the rotational direction and rotational speed of the pull motor 1314-1. In some embodiments, the screw 1313 may be a ball screw. In some embodiments, the effective stroke of the screw 1313 may be 300-1200 mm, the lead may be 5-20 mm, and the diameter may be 16-35 mm. In some embodiments, the perpendicularity of the lead screw 1313 may be less than 0.2 °. In some embodiments, the slider 1312 may be sleeved on the screw 1313 and is in threaded fit with the screw 1313; at least one part of the sliding block 1312 is located in the sliding rail, and the sliding block 1312 can be driven to move up and down along the sliding rail through the rotation (forward rotation or reverse rotation) of the screw rod 1313. Specifically, the control system can send a signal to the pulling driver 1314-2 to control the rotation direction and the rotation speed of the pulling motor 1314-1, and after the speed is reduced by the speed reducer 1314-3, the lead screw 1313 can be driven to rotate in the proper rotation direction and rotation speed through the transmission action of the speed reducer 1314-3 and the coupling 1314-4, so that the slider 1312 is further driven to move up and down at the proper speed, that is, the rotation position of the lead screw 1313 is converted into the vertical displacement of the slider 1312. In some embodiments, the pull speed of the pull motor 1314-1 can be 0.1-20 mm/h, the fast pull speed can be 0.1-3600 mm/h, and the precision is more than 0.01 mm/h.

In the embodiment of the present application, as shown in fig. 4, the weighing device 133 may be configured to detect the weight of the crystal on the lifting rod 120, and the weighing device 133 may be disposed on the sliding block 1312, and the up-and-down movement of the sliding block 1312 may drive the weighing device 133 to move up and down. In some embodiments, the weighing device 133 may be disposed on the sliding block 1312 by bolting, welding, hinging, clamping, or the like, or the weighing device 133 may be placed on the sliding block 1312 without any type of connection, and may be stabilized on the sliding block 1312 only by the weight of the weighing device 133. In some embodiments, the control system may have a signal connection with the weighing device 133 for receiving an output signal of the weighing device 133. In some embodiments, the output signal of the weighing device 133 may be a weight signal of a crystal on the lifting rod 120. In some embodiments, the output signal of the weighing device 133 may be output through a mercury slip ring. By receiving the output signal of the weighing device 133, the control system can determine the weight of the crystal, the increase speed of the weight of the crystal, and the like, and further determine the crystallization speed of the crystal, and according to the crystallization speed of the crystal, the control system can further determine the temperature of the thermal field and send a control signal to the power management part of the heating coil to control the temperature of the thermal field; meanwhile, the control system can control the moving direction and/or the moving speed of the pulling assembly 131 and/or the rotating assembly 132 according to the requirements of the crystal growth process parameters, thereby realizing the automatic control of the crystal growth.

In some embodiments, the rotating assembly 132 may include a second driving unit 1321 and a transmission assembly 1322, and the second driving unit 1321 can drive the weighing device 133 to rotate through the transmission assembly 1322 to control the rotation of the lifting rod 120. In some embodiments, the weighing device 133 can rotate at 0.1-88 rpm with an accuracy of 0.1 rpm. In some embodiments, drive assembly 1322 may include a pulley 1322-1 and a belt 1322-2. In some embodiments, the second driving unit 1321 may include a rotary motor 1321-1, a rotary driver 1321-2, and a mounting block 1321-3, and the rotary motor 1321-1 and the rotary driver 1321-2 may be fixedly disposed (e.g., bolted, welded, hinged, etc.) to the slider 1312 through the mounting block 1321-3. In some embodiments, an output rotation shaft of the second driving unit 1321 is connected to a rotation shaft of the pulley 1322-1, and the rotation direction and the rotation speed of the pulley 1322-1 can be controlled by controlling the rotation direction and the rotation speed of the rotating motor 1321-1. In some embodiments, one or more belts may be disposed around the pulley 1322-1 and the weighing device 133, and the pulley 1322-1 may rotate the weighing device 133 through the belt connection. Specifically, the control system may send a signal to the rotary driver 1321-2 to control the rotation direction and the rotation speed of the rotary motor 1321-1, and further drive the weighing device 133 to rotate at a suitable rotation direction and rotation speed through the transmission of the pulley 1322-1 and the belt 1322-2. In some alternative embodiments, drive assembly 1322 may be a gear and chain drive assembly, including gears and chains. The output rotation shaft of the second driving unit 1321 may be connected with a gear. The outer wall of the weighing device 133 may be provided with a toothed structure, a chain may be sleeved on the gear and the weighing device 133, and the second driving unit 1321 may drive the weighing device 133 to rotate through the gear-chain connection.

In an embodiment of the present application, as shown in fig. 5, the weighing device 133 may include a weighing chamber 1331 and a load cell 1332. In some embodiments, a load cell 1332 may be disposed inside the weighing chamber 1331. In some embodiments, load cell 1332 may include an opto-electronic sensor, a hydraulic sensor, an electromagnetic sensor, a capacitive sensor, a pole-deformation sensor, a vibration sensor, a gyroscopic sensor, a resistive strain gauge sensor, or the like. In some embodiments, one end of the load cell 1332 can be fixedly attached (e.g., bolted, welded, hinged, snapped, etc.) to the lifting bar 120. In some embodiments, the other end of load cell 1332 can be secured (e.g., bolted, welded, hinged, snapped, etc.) to a cover plate of weighing chamber 1331.

In some embodiments, the lifting rod 120 may include at least a center rod 121 and a seed rod 122. In some embodiments, one end of the center pole 121 can be fixedly attached (e.g., bolted, welded, hinged, snapped, etc.) to the weighing chamber 1331. In some embodiments, the stem 121 may pass through a through hole provided on the slider 1312. Bearings may be provided above and below the through-holes to facilitate rotation of the weighing chamber 1331 and thus rotation of the lifting rod 120. In some embodiments, the center rod 121 may have a hollow structure through which the seed rod 122 may pass through the center rod 121. In some embodiments, one end of the seed rod 122 may be coupled to the load cell 1332 (e.g., bolted, welded, hinged, snapped, etc.), and the other end of the seed rod 122 may be used to attach a seed crystal to seed crystal growth. In some embodiments, the seed rod 122 may be made of iridium, molybdenum, ceramic, stainless steel, or other high temperature resistant materials. The seed crystal on the seed rod 122 can be driven to move up and down and rotate in a proper direction and speed by the weighing device 133 moving up and down and rotating in a proper direction and speed, so that the growth speed of the crystal is controlled.

FIG. 6 is a schematic diagram of a crystal growth apparatus 100 according to some embodiments of the present application.

In some embodiments, crystal growth apparatus 100 may further include a sealing sleeve 140. In some embodiments, the lower portion of the sealing sleeve 140 is a retractable sleeve, which is connected to the top of the firebox 110 in a sealing manner (e.g., bolted or welded), and the lifting rod 120 can be located inside the sealing sleeve 140; the top part of the hearth, which is hermetically connected with the sealing sleeve 140, is provided with a through hole for the lifting rod 120 to pass through. In some embodiments, the upper portion of the seal sleeve 140 may be sealingly connected to the lower end face of the slider 1312 by a rotary seal assembly. Since the lifting rod 120 is located in the sealing sleeve 140 and the firebox 110, the lifting rod 120 can freely rotate and move up and down in the sealing sleeve 140 without being affected by the sealing sleeve 140, while ensuring the sealing property of the sealing sleeve 140. In addition, the up-and-down movement of the weighing device 133 can be driven by the up-and-down movement of the sliding block 1312, so that the lifting rod 120 is driven to move up and down, the relative position of the weighing device 133 and the upper part of the sealing sleeve 140 is kept unchanged, and the lower part of the sealing sleeve 140 is a telescopic sleeve, so that the up-and-down movement displacement of the weighing device 133 and the lifting rod 120 can be offset by the pulling up or compressing of the telescopic sleeve at the lower part of the sealing sleeve 140, and the movement of the lifting rod is not. The seed crystal at the lower end of the lifting rod 120 can be isolated from the outside air by arranging the sealing sleeve 140, so that the seed crystal and the hearth 110 are completely in a sealed environment, the growth environment of the crystal is stable, the stability of the crystal crystallization process and the good appearance of the prepared crystal are ensured, and the improvement of the crystal quality is facilitated.

In some embodiments, crystal growing apparatus 100 may further include a vacuum device (not shown) for providing a vacuum environment or an atmosphere below standard atmospheric pressure to the interior of furnace 110. For example, the pressure in the cooled furnace can be 3.3X 10^-3Pa. In some embodiments, the vacuum device may include a vacuum pump and a cylinder of inert gas. In some embodiments, the furnace wall 113 can be provided with a nozzle, and the nozzle can be fixedly connected (e.g., bolted or welded) with the vacuum device through a pipe, so that the inner space of the furnace can be communicated with the vacuum device. The vacuum device, the hearth 110 and the sealing sleeve 140 form a sealed space, the inside of the hearth 110 can be in a vacuum environment or an inert gas pressure environment lower than the standard atmospheric pressure by vacuumizing through a vacuum pump or vacuumizing through a vacuum pump and supplementing inert gas to replace the air in the hearth 110, the raw materials for crystal growth and the seed crystals at the lower end of the lifting rod 120 are in the above gas pressure environment, and the crystal growth process is completed at a certain temperature.

In some embodiments, preparing a crystal by crystal growth apparatus 100 may include the steps of:

(1) installing a furnace frame: installing a furnace frame 115 and a hearth 110 and adjusting the levelness to be 0.05 mm/m;

(2) installing a motion device: installing the movement device 130 and adjusting the verticality of the screw 1313 to be less than 0.2 degrees, and meanwhile, enabling the vertical distance between the upper end and the lower end to be less than 0.5 mm;

(3) adjusting concentricity: installing a heat source 112 (heating coil) and a temperature field 111 according to the requirements of a crystal growth process, wherein the concentricity of the two is less than 1 mm; adjusting the movement device 130 to enable the seed rod 122 of the weighing system 133 to be concentric with the temperature field 111, wherein the concentricity is less than 0.5mm, and the vertical distance between the two ends of the seed rod from top to bottom or from bottom to top is less than 0.5 mm;

(4) vacuumizing; installing a vacuum system, and when the hearth 110 is cooled, starting a vacuum pump to vacuumize for 3 hours to a limit vacuum, or starting the vacuum pump to vacuumize for 3 hours and supplementing inert gas to an inert gas pressure environment lower than or higher than the standard atmospheric pressure so as to detect the tightness of the whole equipment system;

(5) preparing crystal growth: putting materials, loading a crucible and a temperature field according to the process requirements, cleaning a hearth, closing a furnace door, vacuumizing, introducing cooling water, setting various parameters for crystal growth, slowly descending seed crystals in the temperature rising process for preheating, and keeping the distance between the seed crystals and the charge level to be 5-15mm all the time to avoid seed crystal cracking; after the materials are completely melted, slowly sinking the seed crystal to contact with the melt; adjusting the temperature and sinking the seed crystal by 0.5-2mm to fully melt the seed crystal and the melted material, wherein the interface of the seed crystal and the melted material is complete; after the temperature is proper, starting a control program to enter a crystal automatic growth mode;

(6) controlling the crystal growth: the seed rod 122 of the weighing device 133 is connected with the seed crystal, and the crystal is promoted to grow uniformly by controlling the rotating speed of the rotating motor 1321-1, namely controlling the rotating speed of the crystal, and controlling the rotating speed of the pulling motor 1314-1, namely controlling the pulling speed of the crystal growth; controlling the rotating speed of the rotating motor 1321-1 and the pulling motor 1314-1 by controlling the output signal of the system according to the requirements of the crystal growth process parameters so as to meet the requirements of the crystal growth process parameters; in particular, automatic control of crystal growth is achieved through receiving.

The above preparation processes are only examples, and the process parameters involved in the preparation processes may be different in different embodiments, and the sequence of the above steps is not unique, and the sequence between the steps may be adjusted in different embodiments, even if one or more steps are omitted. The above examples should not be construed as limiting the scope of the present application.

The crystal growth apparatus disclosed herein may provide benefits including, but not limited to: (1) the automatic control can be realized in the crystal growth process, and the prepared single crystal material has good structural consistency; (2) the high-quality furnace body material is selected, the welding process is improved, and the sealing property and the corrosion resistance of the hearth can be improved; (3) the hearth structure is simplified, the rapid disassembly and assembly is realized, and the maintenance is more convenient. It is to be noted that different embodiments may produce different advantages, and in different embodiments, any one or combination of the above advantages may be produced, or any other advantages may be obtained.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A crystal growth device is characterized by comprising a hearth, a lifting rod, a sealing sleeve, a movement device and a control system;

a temperature field and a heat source are arranged in the hearth;

at least one part of the lifting rod is positioned in the hearth, and the moving device is in transmission connection with the lifting rod so as to drive the lifting rod to move up and down and/or rotate;

the control system is used for controlling the movement direction and/or the movement speed of the movement device;

the exercise device includes:

a pull-up assembly; the lifting assembly is used for controlling the lifting rod to move up and down;

the lifting assembly comprises: the device comprises a stand column, a slide block, a screw rod and a first driving unit;

the first driving unit is arranged at the top of the upright post;

the upright post is provided with a slide rail;

the screw rod is arranged in parallel with the slide rail, and one end of the screw rod is connected with the first driving unit;

the sliding block is sleeved on the screw rod and is in threaded fit with the screw rod; at least one part of the sliding block is positioned in the sliding rail, and the sliding block can be driven to move up and down along the sliding rail by the rotation of the screw rod;

and a rotating assembly; the rotating assembly is used for controlling the rotation of the lifting rod; the rotating assembly is arranged on the sliding block;

the slider is also provided with a weighing device, the rotating assembly comprises a second driving unit and a transmission assembly, and the second driving unit can drive the weighing device to rotate through the transmission assembly;

the weighing device comprises a weighing chamber and a weighing sensor; the weighing sensor is arranged inside the weighing chamber; the lifting rod at least comprises a middle rod and a seed crystal rod; one end of the middle rod of the lifting rod is fixedly connected with the weighing chamber; the middle rod penetrates through a through hole formed in the sliding block; the middle rod has a hollow structure; a seed rod of the lifting rod penetrates through the middle rod; one end of the seed rod is connected with the weighing sensor; the other end of the seed rod is used for connecting a seed crystal; the other end of the weighing sensor is fixedly connected with a cover plate of the weighing chamber;

one end of the sealing sleeve is hermetically connected with the top of the hearth, and the lifting rod is positioned in the sealing sleeve; the part of the top of the hearth, which is connected with the sealing sleeve in a sealing way, is provided with a through hole so that the lifting rod can pass through the through hole; the other end of the sealing sleeve is connected with the lower end face of the sliding block in a sealing mode.

2. The apparatus according to claim 1, wherein the first cooling structure is provided on at least a portion of the furnace wall.

3. The apparatus according to claim 2, wherein at least a portion of the furnace wall comprises an inner wall and an outer wall, the inner and outer walls enclosing a closed space for filling with a cooling medium; and the outer wall is provided with a cooling medium inlet and a cooling medium outlet.

4. The apparatus of claim 2, wherein the furnace further comprises a furnace door, and wherein the furnace door has a second cooling structure disposed thereon.

5. The apparatus according to claim 4, wherein the furnace door comprises an inner door wall and an outer door wall, the inner door wall and the outer door wall enclosing a closed space, the closed space being filled with a cooling medium; and a cooling medium inlet and a cooling medium outlet are formed in the outer wall of the door.

6. The apparatus of claim 4, wherein at least a portion of the furnace door is transparent.

7. The apparatus of claim 1, wherein the control system is in signal communication with the weighing apparatus for receiving an output signal of the weighing apparatus.

8. The apparatus of claim 1, wherein the drive assembly comprises a pulley and a belt;

the output rotating shaft of the second driving unit is connected with the rotating shaft of the belt pulley;

at least one belt is sleeved on the belt pulley and the weighing device.

9. The apparatus of claim 1, further comprising a vacuum device; the vacuum device is used for providing a vacuum environment or an air pressure environment lower than the standard atmospheric pressure for the interior of the hearth.